I'd say your suspicion is valid. But still just a suspicion. The right thing would be to call the people who live there. (Unless it is a gang that lives there?) You would be justified in talking to the police. It is a reasonable suspicion.
Yes, you should be worried. Call the police and ask whether they have officers in your vicinity who are still inspecting the previous robbery and if they don't, tell them what you saw.
I don't see any big deal about it. I wear trench coats too.
Call the police. Your post is an obvious hoax, and it has been reported.
One house in my neighbourhood had a robbery yesterday.
So today, I went to check the mail (the mailboxes are a bit uphill from my house) when there was a creepy guy in a trench coat and a blue surgical mask standing up there. A car tried to get out from the small road behind there and I think they got out but I'm not sure.
My mom (I'm only 14) said that it's probably no big deal. Should I be worried?